Parechovirus Infection Outbreak Hits Tennessee Newborns, CDC Warns

CDC warns that outbreak of parechovirus infections among infants may be related to the relaxation of pandemic lockdown measures.

Nearly two dozen infants in Tennessee contracted parechovirus infections, a dangerous virus that can lead to brain inflammation and seizures, according to a warning issued by government researchers.

The U.S. Centers for Disease Control and Prevention (CDC) highlighted a new cluster of parechovirus cases from Tennessee in a Morbidity and Mortality Weekly Report issued late last month, alerting parents and caregivers about the particularly dangerous strain of infections that have sickened 23 infants who developed severe complications from the illness.

Human parechovirus (PeV) meningoencephalitis is a non-enveloped RNA virus of the Picornaviridae family. It leads to inflammation of the brain and brain lining, sometimes causing seizures. The virus spreads through respiratory droplets and feces. Initial symptoms include fever, fussiness and poor feeding, but unusual sleepiness and congestion can also occur.

Infants under three months old are disproportionately affected. PeV genotype 3 is responsible for the most severe cases and has been circulating in multiple states. Parechovirus has a pattern of biannual cycle circulation that peaks in the summer months.

The childhood virus was detected in 23 infants in less than a six week span this spring. That is an unusually short amount of time for that many cases to appear. The virus is especially dangerous for children younger than 6 months old.

The parechovirus virus outbreak occurred from April 12 to May 24, 2022, among healthy infants ages 5 days to 3 months. All but one of the infants were admitted to Tennessee’s Children’s Hospital. One child continued to have lasting seizures, 21 fully recovered and one suffered hearing loss. Six other cases were diagnosed at Monroe Carell, Jr. Children’s Hospital, in Nashville, this year; outside of the six-week timeframe for the other cluster.

Nineteen cases were diagnosed at the children’s hospital over five months in 2018; the first year testing for the virus was available. Seven cases were diagnosed from 2019 to 2021. Researchers say the low case count is likely the result of pandemic lockdowns.

It is unclear why there are so many cases this year, but researchers suspect it is linked to effects of coronavirus lockdowns and physical distancing. As lockdowns have lifted, more people are returning to normal activities, including school and daycare, where viruses of this type often circulate easily.

There is no specific treatment for parechovirus. There are no antiviral drugs and no vaccines can prevent it. Treatment largely focuses on maintaining hydration among affected infants and reducing fever as the virus makes its way through their system.

The CDC warning indicates children under three months old, especially those under one month old, are at risk of contracting the parechovirus and experiencing severe illness. They have not developed immunity to the virus, which can spread through the air and contaminated surfaces. It can be brought home by older siblings and easily spread to young infants.

The best ways to prevent parechovirus is by practicing good hygiene, including thorough hand washing, according to the CDC. Limiting the number of people visiting a household interacting with a young baby is important, as well as avoiding kissing the infant’s face and hands.